1. Field of the Invention
The present invention relates to an image transmitter, and more specifically to an image transmitter for compressing incoming image data and transmitting the compressed image data to a receiver via a transmission path.
2. Description of the Background Art
Examples of conventional image compression schemes are the MPEG (Motion Picture Experts Group) scheme and the DVC (Digital Video Cassette) scheme. According to these image compression schemes, incoming image data is subjected to DCT (Discrete Cosine Transform) and variable-length coding on a macro block-by-macro block basis, whereby a high compression rate for the image data may be realized. An implementation example of such an image compression scheme is a moving picture encoder which is disclosed in Japanese Patent Laid-Open Publication No. 7-280911.
However, after the aforementioned moving picture encoder receives one line of pixels arranged along a horizontal direction within an image to be processed, the moving picture encoder may also receive a next line of pixels. As a result, before all of the pixels which compose one macro block are received, the moving picture encoder may receive a number of pixels which are unrelated to that macro block. The receipt of such unnecessary pixels causes a delay time associated with compression processing in conventional moving picture encoders.